If Exeter wondered at half-time what all the fuss was about regarding the Heineken Cup, having taken a 12-10 lead, the first 12 minutes of the second half told them in the most explicit terms.

Exeter had experienced a narrow defeat at the holders Leinster the previous week, while Clermont Auvergne lost to the Irish province in last season's semi-final.

The Chiefs are appearing in the Heineken Cup for the first time. When Clermont made their bow in the tournament at the end of the 1990s, Exeter had taken a first, tentative step towards becoming fully professional. They paced their rise from relative obscurity and now more than hold their own in the Premiership but Clermont, with their pedigree and experience in Europe, marked a step too far.

The Chiefs were worth their lead, four Gareth Steenson penalties punishing Clermont's preference for conceding penalties rather than quick possession at the breakdown. Exeter attacked from deep from the outset, the quick feet of Luke Arscott, Ian Whitten and Jason Shoemark regularly taking them past the first point of the defence.

With the scrum-half Haydn Thomas quick to exploit a hint of a gap around the fringes, the visitors at times looked ponderous and cumbersome, as if they had overdosed on the England football squad's sleeping tablets.

Clermont found themselves squeezed in the scrum and outmanoeuvred at the breakdown but they stayed in touch because of Exeter's principal weakness in the opening half: the lineout. The Chiefs were defending a six-point lead and their own line on 14 minutes and when Whitten forced Napolioni Nalaga into touch just short of the home line, the danger should have passed. Instead, Jamie Cudmore deflected Simon Alcott's throw and Nalaga joined in the driving maul to score the game's opening try.

Exeter were never more dangerous than when Clermont were taking restarts from the halfway line, running the ball out of their own 22 and invariably making ground but they never camped in opposition territory. They indulged in skirmishes rather than a siege, sniping around the fringes without striking a blow at the heart.

The crowd dared to hope when two penalties from Steenson in six minutes put Exeter 12-7 ahead, but the match turned five minutes before the interval when Clermont drove a lineout and Damien Chouly's neat offload to Wesley Fofana saw the centre reach the Exeter 22. When the home No8 Richard Baxter prevented the ball being moved quickly from the subsequent ruck in an offside position, he was sent to the sin bin and Parra duly converted the penalty into points.

The game was markedly different when Baxter returned to the field, although Clermont were only one point ahead thanks to Parra's second penalty. It was as if the Top 14 club's players had received cold water in the face during the interval, playing with a pace, intensity and control they had lacked in the first half.

Now it was Exeter who struggled to get hold of the ball. When they did, their attacks from deep were not just snuffed out but Clermont forced turnovers, two of which led to their second and third tries.

There was an element of fortune about the first: Whitten lost control of the ball in the tackle and Fofana exploited space down the blind-side to run 45 metres to score but he put his right foot on the touchline after a lunging tackle by Tom Johnson and smiled when the referee awarded the try rather than consult the video official.

There was no disputing the third try which again came after Exeter had lost possession. The flanker Julien Bonnaire just kept his feet in play as he finished off a move on the right wing and he had personified the transition in his side: so confrontational and direct that Exeter found themselves playing a game they were not used to.

The Chiefs kept trying; Arscott should have made more of two counterattacks but Clermont's three tries in the final nine minutes, through Sitiveni Sivivatu, Fofana and Nalaga, came when Exeter, because of injuries, had a centre at scrum-half, a back rower in the midfield and a prop at flanker. Worcester next weekend will be very different.